Morphology changes of maxillary molar distalization by clear aligner therapy / Cambios de la morfología en la distalización de molares maxilares mediante terapia con alineadores transparentes

SUMMARY: To evaluate the skeletal, dento-alveolar and soft tissue morphology changes after maxillary molar distalization by clear aligner therapy and identify the significant efficacy of molar distalization,18 patients in conformity with the inclusion criteria were selected. Pre- and post-treatment Cone Beam Computed Tomography (CBCT) were examined to measure the angular and linear parameters. All subjects were completed non-extraction clear aligner treatment by distalizing molars. A paired-t test and independent-samples t-test were performed to observe the difference between before and after treatment and the difference between the first molar and second molar respectively. P-values <0.05 were considered statistically significant. Predicted movement rate was calculated by the formula: (actual movement(mm)/planned movement(mm)) x100%. Most variables of pre- and post-treatment showed no statistical difference(P<0.05), excepting SNA angle (P<0.05) and Upper lip/E-line linear (P<0.01) due to incisor retraction. The first and second molar revealed a translation movement without significant tipping and vertical movement. Clear aligners provided a high predictability (83.44 %) of distalization the maxillary first molar, and 85.14 % of the maxillary second molar. Clear aligners can effectively achieve distal displacement of molars.

RESUMEN: Se seleccionaron 18 pacientes, de acuerdo con los criterios de inclusión, para evaluar los cambios en la morfología esquelética, dentoalveolar y de los tejidos blandos después de la distalización de los molares maxilares, mediante la terapia con alineadores transparentes e así identificar la significativa eficacia de la distalización de los molares. Se examinó a través de tomografía computarizada de haz cónico (CBCT) antes y después del tratamiento para medir los parámetros angulares y lineales. Todos los sujetos completaron el tratamiento con alineadores transparentes sin extracción mediante la distalización de los molares. Se realizó una prueba t pareada y una prueba t de muestras independientes para observar la diferencia entre antes y después del tratamiento y la diferencia entre el primer molar y el segundo molar, respectivamente. Los valores de p<0,05 se consideraron estadísticamente significativos. La tasa de movimiento prevista se calculó mediante la fórmula: (movimiento real (mm)/movimiento planificado (mm)) x 100 %. La mayoría de las variables de pre y postratamiento no mostraron diferencia estadística (P<0,05), excepto el ángulo SNA (P<0,05) y el labio superior/línea E lineal (P<0,01) debido a la retracción del incisivo. El primer y segundo molar revelaron un movimiento de traslación sin inclinación significativa y movimiento vertical. Los alineadores transparentes proporcionaron una alta previsibilidad (83,44 %) de la distalización del primer molar superior y del 85,14 % del segundo molar superior. Los alineadores transparentes pueden lograr efectivamente el desplazamiento distal de los molares.

Silencing HIF-1α reduces the adhesion and secretion functions of acute leukemia hBMSCs

Hypoxia inducible factor-1α (HIF-1α) is an important transcription factor, which plays a critical role in the formation of solid tumor and its microenviroment. The objective of the present study was to evaluate the expression and function of HIF-1α in human leukemia bone marrow stromal cells (BMSCs) and to identify the downstream targets of HIF-1α. HIF-1α expression was detected at both the RNA and protein levels using real-time PCR and immunohistochemistry, respectively. Vascular endothelial growth factor (VEGF) and stromal cell-derived factor-1α (SDF-1α) were detected in stromal cells by enzyme-linked immunosorbent assay. HIF-1α was blocked by constructing the lentiviral RNAi vector system and infecting the BMSCs. The Jurkat cell/BMSC co-cultured system was constructed by putting the two cells into the same suitable cultured media and conditions. Cell adhesion and secretion functions of stromal cells were evaluated after transfection with the lentiviral RNAi vector of HIF-1α. Increased HIF-1α mRNA and protein was detected in the nucleus of the acute myeloblastic and acute lymphoblastic leukemia compared with normal BMSCs. The lentiviral RANi vector for HIF-1α was successfully constructed and was applied to block the expression of HIF-1α. When HIF-1α of BMSCs was blocked, the expression of VEGF and SDF-1 secreted by stromal cells were decreased. When HIF-1α was blocked, the co-cultured Jurkat cell’s adhesion and migration functions were also decreased. Taken together, these results suggest that HIF-1α acts as an important transcription factor and can significantly affect the secretion and adhesion functions of leukemia BMSCs.

Silencing HIF-1α reduces the adhesion and secretion functions of acute leukemia hBMSCs.

Hypoxia inducible factor-1α (HIF-1α) is an important transcription factor, which plays a critical role in the formation of solid tumor and its microenvironment. The objective of the present study was to evaluate the expression and function of HIF-1α in human leukemia bone marrow stromal cells (BMSCs) and to identify the downstream targets of HIF-1α. HIF-1α expression was detected at both the RNA and protein levels using real-time PCR and immunohistochemistry, respectively. Vascular endothelial growth factor (VEGF) and stromal cell-derived factor-1α (SDF-1α) were detected in stromal cells by enzyme-linked immunosorbent assay. HIF-1α was blocked by constructing the lentiviral RNAi vector system and infecting the BMSCs. The Jurkat cell/BMSC co-cultured system was constructed by putting the two cells into the same suitable cultured media and conditions. Cell adhesion and secretion functions of stromal cells were evaluated after transfection with the lentiviral RNAi vector of HIF-1α. Increased HIF-1α mRNA and protein was detected in the nucleus of the acute myeloblastic and acute lymphoblastic leukemia compared with normal BMSCs. The lentiviral RANi vector for HIF-1α was successfully constructed and was applied to block the expression of HIF-1α. When HIF-1α of BMSCs was blocked, the expression of VEGF and SDF-1 secreted by stromal cells were decreased. When HIF-1α was blocked, the co-cultured Jurkat cell's adhesion and migration functions were also decreased. Taken together, these results suggest that HIF-1α acts as an important transcription factor and can significantly affect the secretion and adhesion functions of leukemia BMSCs.

Identification of an antifungal metabolite produced by a potential biocontrol Actinomyces strain A01 / Identificação de um metabólito antifúngico produzido pela cepa Actinomyces A01

Actinomyces strain A01 was isolated from soil of a vegetable field in the suburb of Beijing, China. According to the morphological, cultural, physiological and biochemical characteristics, and 16S rDNA sequence analysis, strain A01 was identified as Streptomyces lydicus. In the antimicrobial spectrum test strain A01 presented a stable and strong inhibitory activity against several plant pathogenic fungi such as Fusarium oxysporum, Botrytis cinerea, Monilinia laxa, etc. However, no antibacterial activity was found. In pot experiments in greenhouse, the development of tomato gray mold was markedly suppressed by treatment with the fermentation broth of the strain A01, and the control efficacy was higher than those of Pyrimethanil and Polyoxin. A main antifungal compound (purity 99.503 percent) was obtained from the fermentation broth of strain A01 using column chromatography and HPLC. The chemical structural analysis with UV, IR, MS, and NMR confirmed that the compound produced by the strain A01 is natamycin, a polyene antibiotic produced by S. chattanovgensis, S. natalensis, and S. gilvosporeus, widely used as a natural biological preservative for food according to previous reports. The present study revealed a new producing strain of natamycin and its potential application as a biological control agent for fungal plant diseases.

A cepa Actinomyces A01 foi isolada do solo de um campo agrícola no subúrbio de Beijing, China. De acordo com as características morfológicas, culturais, fisiológicas e bioquímicas, e análise da sequência 16S rDNA , a cepa A01 foi identificada como Streptomyces lydicus. Nos testes de espectro antimicrobiano, a cepa A01 apresentou atividade inibitória intensa e estável contra vários fungos patogênicos para plantas, como Fusarium oxysporum, Botrytis cinerea, Monilia laxa, etc. Entretanto, não foi encontrada atividade antibacteriana. Em experimentos em estufas, o desenvolvimento do fungo cinza do tomate foi fortemente inibido pelo tratamento com o caldo de fermentação da cepa A01, com eficiência superior à do pyremethanil e polyoxin. Por cromatografia em coluna e HPLC, obteve-se um composto fúngico (pureza 99,503 por cento), cuja análise estrutural por UV, IR, MS e NMR revelou ser natamicina, um antibiótico polienico produzido por S. chattanovgensis, S. natalensis e S.gilvosporeus, empregado como conservador biológico natural em alimentos. O presente estudo relata a detecção de uma nova cepa produtora de natamicina e sua aplicação potencial como um agente de controle biológico de doenças fúngicas em plantas.